Accuracy
How many seconds a day your watch gains or loses, heard through your phone’s microphone.

Maurice de Mauriac · Zurcher Chrono Modern Titan Schwarz Blauer Zeiger
ChangeZürcher Chrono Modern Titan Schwarz | Blauer Zeiger
Somewhere quiet, lay the watch caseback up on something soft. Rest the bottom edge of your phone on the caseback and keep both still.